It is known in the technical sector relating to automatic filling of containers of various types, size and shape, automatic filling machines are used, which are able to deliver, by means of controlled valves associated with delivery outlets, a predetermined metered quantity of the fluid to be supplied to the empty container conveyed opposite said outlet by conveying means of various types.
It is also known that the fluids to be supplied to the containers to be filled may have physical and chemical characteristics which are very different from one another the such as to determine the need for providing special valve/outlet unit for each type of fluid.
For example, in the case of liquid, viscous and foam-producing products, it is necessary to provide outlets which have a wide delivery nozzle and inside which there must be inserted a flow reducer, in order to slow down the delivery and prevent generation of foam, and a jet-breaking screen for retaining the droplets of product and preventing them from falling droplets between advance feeding of the filled container and arrival of the next empty container.
In the case of viscous products, on the other hand, the outlet must have a delivery nozzle which is narrow, but provided with a strand-breaking element which prevents the strand of product which is left hanging from the outlet at the end of each delivery operation from being dragged between one container and the next one.
In addition to the outlets of the known type there is the problem arising from the need to interrupt the supply, under pressure, of the product to the machine so as to be able to perform change-over of the outlet itself when there is a variation in the type of product, without causing losses of the latter.